JP3644530B2 - Chair rocking structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rocking structure for a chair having a backrest that can be tilted rearward.
[0002]
[Prior art]
In a chair having a backrest that can be tilted rearwardly, a gas cylinder is generally used as a means for holding the backrest in an arbitrary rearward tilting posture, but this causes a problem in terms of cost and space.
[0003]
Therefore, for example, as described in Japanese Utility Model Publication No. 63-28921 and Japanese Utility Model Publication No. 3-37465, a friction plate is sandwiched between a plurality of movable plates that move in conjunction with the tilting of the backrest, and the movable plate and There has been proposed a lock device in which the backrest can be held in an arbitrary backward tilted posture by bringing the friction plate into close contact with a cam-type or screw-type pressing tool and holding the movable plate immovable.
[0004]
[Problems to be solved by the invention]
This lock device using a movable plate and a friction plate has the appearance of a variable frequency variable condenser such as a radio, and has the advantage of being able to adjust the back tilt angle of the backrest in a stepless manner while having a simple configuration. On the other hand, in the conventional variable condenser lock device, the parts such as the movable plate and the friction plate are divided into pieces before being assembled to the chair, and these divided pieces are attached to the seat receiving body. Therefore, there is a problem that the assembly work of the chair is troublesome.
[0005]
On the other hand, the backrest tilts backward against the spring means, but as the back tilt angle of the backrest increases, the human body tends to slide backwards. The increasing rate of the moment acting on the backrest tends to be larger than the increasing rate. For this reason, when the seated person leans back on the backrest, the backrest tilts backward in a very short time with a feeling of a stone, and there is a problem of lack of comfort.
[0006]
For this, it is considered that the spring force of the spring means should be increased. However, simply increasing the spring force of the spring means makes it difficult for the backrest to tilt excessively in the initial stage of rearward tilting. It will be lacking. In other words, it has been impossible to achieve a comfortable feeling by applying a suitable reaction force to the back of a person over the entire back tilt of the backrest by simply adjusting the initial elastic force of the spring means.
[0007]
Furthermore, if the backrest simply tilts backward against the elastic resistance of the spring means, the elastic force of the spring means acts too sensitively on the person's back, so the person's back is gently supported. The state could not be created, and there was a limit to improving the comfort in the rocking state.
[0008]
The present invention aims to improve these current situations.
[0009]
[Means for Solving the Problems]
According to the first aspect of the present invention, a seat and a backrest are attached to a seat support provided at the upper end of the leg so that at least the backrest tilts backward, and further, the seat support is tilted after the backrest. In a chair provided with a resistance applying device provided with an appropriate number of movable plates that move in conjunction and a friction plate that provides resistance to the movement of the movable plate, the movable plate and the friction plate are integrated into a case. Thus, the resistance applying means is unitized, and the case is fixed to the seat support.
[0010]
The resistance applying means in the present invention may function as a lock means for holding the backrest in an arbitrary backward tilting posture. However, as described in claim 2, at least the movable plate in a state in which the rearward tilting of the backrest is allowed. It is preferable to set to a state in which a frictional resistance can be imparted.
[0011]
Also, when the resistance applying means functions as a locking means, the resistance force is switched between a locked state in which the friction plate is strongly pressed against the movable plate so that the movable plate cannot be moved, and a free state in which the movable plate can freely move. It is necessary to provide an adjusting device (switching device). Furthermore, the resistance adjustment device that adjusts (switches) the degree of adhesion of the friction plate to the movable plate allows the movable plate to move freely without resistance, and allows movement in a state where an appropriate resistance is applied. It is also possible to set so that at least two states can be selected from the three states of the intermediate state and the locked state where the movable plate cannot move at all.
[0012]
[Operation and effect of the invention]
According to the present invention, since the resistance applying means including the movable plate and the friction plate is unitized, the assembly of the chair can be performed efficiently.
[0013]
According to the second aspect of the present invention, when a seated person leans against the backrest, the backrest can be tilted for an appropriate period of time because resistance to the tilting of the backrest is imparted by the frictional resistance between the movable plate and the friction plate. It can maintain the hysteresis loss function that tilts by applying a tilt, and in other words, the backrest can be tilted while gently supporting the person's back, and as a result, the comfort in the locked state is markedly improved. Can be improved.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0015]
<< First Embodiment (FIGS. 1 to 10) >>
1 to 10 show a first embodiment, FIG. 1 is a right side view of a chair, FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. 3 is a sectional view taken along line III-III in FIG. 4 is a sectional view taken along the line IV-IV in FIGS. 2 and 5, FIG. 5 is a sectional plan view of the main part, FIG. 6 is a sectional view taken along the line VI-VI in FIGS. FIG. 8 is a diagram showing an operation, and FIGS. 9 and 10 are diagrams showing an assembling procedure.
[0016]
As shown in FIGS. 1 to 3, the chair includes a seat receiving body 2 fixed to the upper end of a pedestal (gas cylinder) 1, a seat body 3, and a backrest 4. The seat receiver 2 is formed in a box shape opened upward, and its rear portion is fitted to the pedestal 1. In the front part of the left and right side plates 2a in the seat receiver 2, a long hole 5 inclined in a side view is opened, while a U-shaped base 6 in a front view is fixed to the lower surface of the seat body 3. The first shaft 7 is passed through the front end portions of the left and right side plates 6 a of the base 6 and the long holes 5 of the seat receiver 2. A guide bush 8 made of synthetic resin is fitted in the long hole 5 of the seat support 2.
[0017]
The backrest 4 is attached to a back support 9 that is substantially L-shaped when viewed from the side, and the front end of the back support 9 is rotatably attached to the rear of the seat support 2 by the second shaft 10. A midway portion of the support 9 and the side plate 6a of the base 6 of the seat 3 are rotatably connected by a third shaft 11. As shown in the figure, the back support 9 is not limited to an integral type, but may be a type in which a pair is disposed on the left and right sides of the seat support 2.
[0018]
Inside the seat receiver 2, a coil spring 12 as an example of a spring means is disposed so as to extend in the front-rear direction. The front end of the coil spring 12 is supported by a front spring receiver 13 fitted on the first shaft 7, and the rear end of the coil spring 12 is supported by a rear spring receiver 15 supported by a wedge member 14 so as to move back and forth. It is supported. The spring means is not limited to the coil spring, and the spring means such as the coil spring 12 may not be arranged as shown.
[0019]
As can be understood from the above description, when a seated person leans against the backrest 4, the backrest 4 and the back support 9 are tilted rearward about the second shaft 10 against the coil spring 12, and the seat 3 is guided by the long hole 5 and tilts backward while moving backward. That is, the backward movement and rearward tilting of the seat body 3 and the rearward tilting of the backrest 4 are synchronized (linked). Needless to say, the rate at which the seat back 3 tilts backward is smaller than the rate at which the backrest 4 tilts backward.
[0020]
As shown in FIG. 2 and FIGS. 4 to 10, resistance imparting means 16 that suppresses the back and forth tilting movement of the backrest 4 is provided inside the seat receiver 2. The resistance applying means 16 includes three movable plates (movable bodies) 17 made of a metal plate extending in the front-rear direction, and a round hole 18 that fits in the first shaft 7 is formed at the front of each movable plate 17. Vacant. A long hole 19 extending in the front-rear direction is formed at a site from the rear end of each movable plate 17, and a support shaft 20 passes through the long hole 19. A ring-shaped friction plate (friction body) 21 is fitted into a portion of the support shaft 20 between the adjacent movable plates 17. The friction plate 21 can be made of various materials such as a material having a high frictional resistance such as a synthetic resin or rubber, or a metal plate made of grease.
[0021]
Further, the rear part of each movable plate 17 and the friction plate 21 are covered with a case 22 having a U-shaped opening facing downward (may be referred to as a holder), and the support shaft 20 is attached to the left and right side plates of the case 22. It penetrates. The case 22 is fastened to the seat receiver 2 with an appropriate number of screws 23. Collars 24 and 25 are respectively fitted to both sides of the support shaft 20 across the group of the movable plate 17 and the friction plate 21. Of these, the collar 24 on the side close to the coil spring 12 passes through the case 22. A cylindrical portion 24a extending outward is integrally provided (the collar 24 and the cylindrical portion 24a may be separate), and a flange 20a is formed on the support shaft 20 to prevent the cylindrical portion 24a from coming off. . Further, a spring 26 for returning to the free state is fitted into the cylindrical portion 24a.
[0022]
An end portion of the support shaft 20 that is close to the side plate 2a of the seat receiving body 2 is exposed to the outside of the case 22, and a cam 27 that is formed in a U shape in plan view is covered on the end portion of the support shaft 20. The cam 27 is rotatably attached to the support shaft 20 with a pin (screw) 28 extending in the front-rear direction. The cam 27 is formed with first and second cam surfaces 29 and 30 that abut against the side surface of the case 22. By rotating the cam 27 around the pin 28, the two cam surfaces 29 are formed. , 30 can be selectively applied to the side of the case 22. A lever 32 is screwed to the cam 27 through a vertically long window hole 31 formed in the side plate 2a of the seat receiver 2.
[0023]
As shown in FIG. 7, the shortest distance L1 from the axial center of the pin 28 to the first cam surface 29 is set to be larger than the shortest distance L2 from the axial center of the pin 28 to the second cam surface 30. Yes. Therefore, when the cam 32 is rotated by operating the lever 32, the support shaft 20 slides in the longitudinal direction thereof, whereby the movable plates 17 and the friction plates 21 can be brought into close contact with each other or separated from each other. it can.
[0024]
In the present embodiment, in the state where the first cam surface 29 is in contact with the case 22, no frictional resistance is generated between the movable plate 17 and the friction plate 21, and the second cam surface 30 is located on the case 22. When abutting against the side surface, as shown in FIG. 8, the movable plate 17 and the friction plate 21 are brought into close contact with each other, and a frictional resistance is generated between the movable plate 17 and the friction plate 21, and the frictional resistance is resisted. Thus, the movable plate 17 is set to be allowed to move (the backrest 4 can tilt).
[0025]
Therefore, when a seated person leans against the backrest 4, the backrest 4 tilts backward against the elastic restoring force of the coil spring 12, and a frictional resistance is generated between the movable plate 17 and the friction plate 21. As a result, the backrest 4 does not tilt backward in a short time like a stone, but slowly tilts back over a certain amount of time. As a result, the hysteresis loss effect is exhibited and the rocking state is comfortable. Can be secured.
[0026]
In attaching the resistance applying means 16, first, as shown in FIG. 9, the case 22 to which the movable plate 17, the friction plate 21, the support shaft 20, and the cam 27 are attached is fixed to the seat receiver 2 with screws 23. After that, the lever 32 is inserted into the cam 27 at the root and attached, and before or after this, as shown in FIG. 10, the first shaft 7 may be passed through the round hole 18 of each movable plate 17 (FIG. 9). In this stage, the screw 23 may be temporarily fixed, and the screw 23 may be finally tightened after the first shaft 7 is inserted through the movable plate 17).
[0027]
Thus, since the resistance applying means 16 in which the parts such as the movable plate 17 and the friction plate 21 are attached to the case 22 is unitized, the assembly work of the chair can be performed efficiently. The number of movable plates 17 and friction plates 21 can be arbitrarily set as necessary. The shape can also be set as appropriate.
[0028]
<< Second Embodiment (FIGS. 11 to 12) >>
11 and 12 show a second embodiment. In this embodiment, the male screw portion 20 a is formed on the support shaft 20, and this is screwed into the case 22, and the support shaft 20 is rotated by the handle 33, whereby the degree of contact between the movable plate 17 and the friction plate 21 is increased. It can be adjusted steplessly.
[0029]
In this embodiment, by adjusting the degree of screwing of the support shaft 20, as shown in FIG. 11, the movable plate 17 has no frictional resistance at all, and as shown in FIG. It is possible to switch between an intermediate state in which frictional resistance is applied while allowing movement, and a locked state in which the movable plate 17 is fixed in a state in which it cannot move at all.
[0030]
In the intermediate state, it is also possible to adjust the magnitude of the resistance according to the user's preference (by adjusting the initial elastic force of the spring means and adjusting the resistance, a hysteresis loss state appropriately corresponding to the preference of the person can be obtained. realizable). In this example, the window hole 31 of the seat receiver 2 is cut upward. Instead of attaching the handle 33 directly to the support shaft 20, a rod with a handle may be attached to the support shaft 20.
[0031]
«Third embodiment (Fig. 13)»
FIG. 13 shows a third embodiment. In this embodiment, pressing rings 34 and 35 are arranged on both sides of the group of the movable plate 17 and the friction plate 21 fitted to the support shaft 20, and a spring 36 is interposed between one pressing ring 34 and the inner surface of the case 22. A cylindrical end face cam 40 having high, middle, and low three-stage cam surfaces 37, 38, and 39 is fitted between the other presser ring 35 and the inner surface of the case 22. The foot portions 35a that can selectively contact the cam surfaces 37, 38, and 39 of the cam 40 are integrally provided.
[0032]
Further, a rod 41 attached with a handle (not shown) is attached to the cam 40 so as not to be relatively rotatable. The support shaft 20 and the other pressing ring 35 are held so as not to rotate. In this embodiment, when the lower cam surface 37 of the cam 40 is made to correspond to the foot portion 35a of the other pressing ring 35, no frictional resistance acts on the movable plate 17, and the backrest 4 is a coil spring. It is in a free state that tilts backward against only 12.
[0033]
On the other hand, in the state where the handle 33 is rotated and the middle cam surface 38 of the cam 40 is brought into contact with the foot portion 35 a of the other pressing ring 35, each movable plate 17 and the friction plate 21 are appropriately adjusted via the spring 36. The movable plate 17 is in close contact with the force, and a frictional resistance is generated in an intermediate state in which the movable plate 17 is allowed to move. Further, in a state where the high cam surface 39 of the cam 40 is in contact with the foot portion 35 a of the other pressing ring 35, each movable plate 17 and the friction plate 21 are in close contact with each other via the spring 36, and the movable plate 17. Is locked immovable.
[0034]
≪Others≫
As shown in FIG. 14 as a fourth embodiment, the degree of close contact between the movable plate 17 and the friction plate 21 may be adjusted by a screw-type handle 33 and a spring 36. Further, as shown in FIG. 15 as the fifth embodiment, the movable plate 17 may be formed with a notch groove 42 fitted from above onto the first shaft 7. It becomes even easier.
[0035]
As mentioned above, although embodiment of this invention was described, this invention can be embodied in various aspects. For example, the present invention can be applied not only to a type in which the backrest and the seat are synchronized but also to a chair in which only the backrest tilts backward. In the case of a synchro-type chair, the second axis may be slid in the front-rear direction. The case may be fastened to the seat receiver with a fastener such as a rivet other than a screw, or may be welded.
[Brief description of the drawings]
FIG. 1 is a right side view of a chair according to a first embodiment.
2 is a cross-sectional view taken along the line II-II in FIG.
3 is a cross-sectional view taken along line III-III in FIG.
4 is a cross-sectional view taken along the line IV-IV in FIGS. 2 and 5. FIG.
FIG. 5 is a cross-sectional plan view of resistance applying means.
6 is a cross-sectional view taken along the line VI-VI in FIGS. 2 and 5. FIG.
FIG. 7 is a partially broken front view of the cam.
FIG. 8 is a diagram showing a state where resistance is applied.
FIG. 9 is a diagram showing an assembling procedure.
FIG. 10 is a diagram showing an assembling procedure.
FIG. 11 is a cross-sectional plan view in a free state according to the second embodiment.
FIG. 12 is a plan sectional view showing a state where resistance is applied in the second embodiment.
FIG. 13 is a plan sectional view showing a third embodiment.
FIG. 14 is a plan sectional view showing a fourth embodiment.
FIG. 15 is a plan sectional view showing a fifth embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Pillar 2 Seat receiving body 3 Seat 4 Backrest 7 1st axis | shaft 9 Back support body 12 Coil spring 16 Resistance provision means 17 Movable plate 20 Shaft 22 Case 23 Screw 24, 25 Collar 27 Cam 32 Lever

Claims (2)

A seat and a backrest are attached to a seat support provided at the upper end of the leg so that at least the backrest tilts backward, and an appropriate number of movable plates that move in conjunction with the rear tilt of the backrest on the seat support And a chair provided with a resistance applying device provided with a friction plate for applying resistance to the movement of the movable plate,
A rocking structure for a chair, wherein the movable plate and the friction plate are integrated into a case so as to unitize the resistance applying means and the case is fixed to a seat support. 2. The chair locking structure according to claim 1, wherein the resistance applying means is set to a state in which a frictional resistance can be applied to the movable plate at least in a state in which the back tilt of the backrest is allowed.

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